diff --git a/src/components/style/selector_matching.rs b/src/components/style/selector_matching.rs
index 36e676d007e..f36decd8fc7 100644
--- a/src/components/style/selector_matching.rs
+++ b/src/components/style/selector_matching.rs
@@ -577,7 +577,7 @@ fn matches_generic_nth_child<N: TreeNode<T>, T: TreeNodeRefAsElement<N, E>, E: E
     }
 
     let (n, r) = (index - b).div_rem(&a);
-    n >= 0 && (a * n == index - b) 
+    n >= 0 && r == 0
 }
 
 #[inline]